Evidence. What is it?
The dictionary defines evidence as the means of proving or disproving
something. In other words, evidence is used as proof. In science evidence is
something that has been observed and measured. If you looked at a thermometer
placed on a tree outside and observed that it read 7 degrees Celsius, then you
could say "The outside temperature is 7 degrees Celsius" and it would
be considered evidence.

Inferences. What are
they? The dictionary says that an inference is a statement that is derived from
evidence. It is a product of reasoning. It is not a result of direct
observation or measurement. From the fact that it is 7 degrees Celsius outside,
you could infer that it is winter. Or you could infer that the person making
the observation lives in Alaska. Both of these possible inferences would be
based on the evidence (7 degrees Celsius outside) and would be a result of you
using your reasoning skills to make a conclusion.

The
cyclic movement of carbon atoms in the biosphere has a tremendous impact on
your life, whether you are aware of it or not. Were it not for the carbon cycle
you would have no food to eat, no gasoline for your car, and no paper to write
on. In fact, you would not exist. The carbon cycle impacts your life in a
"big way".

Just as the carbon cycle
impacts your life, you also have an impact on it. The fuels you use, the
products you buy, and the legislation you support all influence the carbon
cycle. In the assignment that follows you will learn how people in general and
you in particular, affect the carbon cycle. You will do so by identifying
evidence and stating inferences.

Learning
the difference between evidence and inference is difficult at first so let’s
practice. Read the paragraph below:

The carbon dioxide
content of the atmosphere is gradually and steadily increasing. The increase in
CO2 probably began with the start of the industrial revolution.
Samples of air trapped over the centuries in the glacial ice of Greenland show
no change in CO2 content until 300 years ago. The concentration of
carbon dioxide in the atmosphere continues to increase. The CO2 concentration at the summit of Mauna Loa in Hawaii from was about 318 part per
million (ppm) 1958. In 1999 it was approximately 371 ppm. . Since measurements
of atmospheric CO2 began late in the nineteenth century, its
concentration has risen over 20%. This increase is surely
"anthropogenic"; that is, caused by human activities.

Look
at the first sentence. Is it evidence or inference? Measurements of the Earth’s
atmosphere indicate that the carbon dioxide content of the atmosphere is indeed
increasing. Because the statement is based on measurements, it is considered
EVIDENCE.

Look
at the second sentence now. Is it evidence or inference? The sentence seeks to
explain the increase in atmospheric carbon dioxide content. It is not based on
measurement. It is INFERENCE.

Take a little quiz.
Identify the remaining sentences as either EVIDENCE or INFERENCE.

1.Samples of air trapped
over the centuries in the glacial ice of Greenland show no change in CO2 content until 300 years ago.”

2.The concentration of
carbon dioxide in the atmosphere continues to increase. The CO2 concentration at the summit of Mauna Loa in Hawaii from was about 318 part per
million (ppm) 1958. In 1999 it was approximately 371 ppm.”

3.Since measurements of
atmospheric CO2 began late in the nineteenth century, its
concentration has risen over 20%.

How did you do? The
first three statements are based on measurements. They are considered evidence.
The last sentence uses reasoning to explain the evidence therefore it is
inference.

SO….Let’s
do a little review. A statement of evidence is a statement of a measurement or direct observation. An inference explains or extrapolates conclusions from the evidence;
it often tries to explain WHY the evidence is what it is or what a probable
result of the evidence may be. Inferences are often accompanied by words such
as:

….is thought

….seem

…..estimate

…..surely

…...probably

…...maybe.

Now, it is time for the
part of the assignment that you will turn in to me.

Assignment:

Your
task is to find and correctly identify evidence and inference statements in the
following article. You need to write the
entire sentence AND label it as “evidence” or “inference”.